Sealed compressor with motor standard spacer providing bearing mount

ABSTRACT

A spacer is positioned between an outer periphery of a motor stator, and the inner periphery of a center shell for a sealed compressor. The spacer allows a relatively small diameter motor to be used in a relatively large diameter center shell. The spacer includes a bearing mount in a lower plate, and a plurality of axially extending fingers positioned between the stator and the center shell. The spacer also includes a stop for proper positioning of the stator within the center shell.

BACKGROUND OF THE INVENTION

This application relates to a sealed compressor, wherein a spacer ispositioned between a motor stator and an internal wall of a cylindricalshell, such that smaller diameter motors can be utilized. The spacerprovides a motor stop surface and mounts a bearing.

Sealed compressors are known, and typically include an electric motordriving a shaft to drive a pump unit. One relatively popular type ofsealed compressor is a scroll compressor.

It is known to seal a housing for the compressor such that refrigerantcan circulate within the compressor housing. As an example, suctionrefrigerant on its way to the compressor pump unit is often circulatedover the cooled motor. This requires the housing shell to behermetically sealed. Typically, a cylindrical shell is attached to endcaps at each axial end.

The cylindrical shell must have a particular diameter for a variety ofreasons. One reason might be the size of the compressor pump unit. Thissometimes requires an undesirably large diameter motor.

Thus, the size of the compressor shell has limited the available motors,and often required unnecessarily large electric motors. It has beenproposed in the prior art to put a cylindrical ring as a spacer betweenan outer periphery of the motor stator and an inner periphery of thecylindrical shell, to allow the use of a smaller motor. However, theproposed structure is generally a cylindrical ring, and would raiseassembly issues.

SUMMARY OF THE INVENTION

In a disclosed embodiment of this invention, a spacer is positionedbetween a stator of an electric motor, and an interior wall of a centershell. The spacer allows a motor with a smaller outer diameter than theinner diameter of the center shell, to be secured within the centershell. The spacer includes a relatively flat plate at an end of thesealed compressor remote from a compressor pump unit, and having abearing mount. In this manner, a bearing for supporting a shaft drivenby an electric motor can be mounted into the spacer, which simplifiespositioning and centering of the motor and the shaft relative to thecenter shell. In other features, the spacer is formed of a plurality offingers extending axially from the plate, and which are positionedbetween the outer periphery of the motor and the center shell. Also, astop is formed on the spacer to provide an axial stop for the motorstator as it moves within the center shell.

These and other features of the present invention can be best understoodfrom the following specification and drawings, the following of which isa brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of the sealed compressor incorporating the presentinvention.

FIG. 2 is a perspective view of a spacer according to an embodiment ofthis invention.

FIG. 3 is an assembly step according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a sealed compressor 20 incorporating a compressor pump unit22, and an end cap 24 secured to a cylindrical center shell 26. A lowerend cap 28 is secured to an opposed end of the center shell 26. Thecenter shell has an inner diameter which is defined in part by the sizeof the compressor pump unit 22. A motor has a stator 30 with a smallerouter diameter than the inner diameter of the shell 26. A spacer 38 ispositioned between an inner periphery of the center shell 26 and anouter periphery of the stator 30. The stator 30 drives a rotor 32 whichin turn drives a shaft 34. As shown in FIG. 1, the shaft 34 is supportedwithin a bearing 36. The bearing 36 is supported in a plate-like lowerportion 42 of the spacer 38. A bearing member 54 is secured within anopening 44. A plurality of fingers 41 extend axially towards the pumpunit 22 from the plate 42, and are positioned intermediate the stator 30and the center shell 26. As can be seen, a stop 40 provides a stopsurface to properly axially position the stator 30.

As shown in FIG. 2, the fingers 41 include radially outwardly extendingportions 57 and radially inwardly extending portions 59. As can beappreciated, radially outwardly extending portions 57 abut the innerperiphery of the center shell 26 and radially inwardly extendingportions 59 abut the outer periphery of the stator 30.

As also shown, the plate 42 has a downwardly extending bearing mount 44for receiving the bearing 54. Ribs 43 are formed on the plate to providea strong construction.

As shown in FIG. 3, the center shell 26 may be mounted downwardly overthe fingers 41, with the fingers 41 having a chamfered top end 80 tofacilitate the downward movement. The center shell 26 moves downwardlytowards the lower end cap 28 to a position 100. As can be appreciated,the stator can then be moved into the legs 41, and will be secured bythe legs 41, and supported on the pump 40.

The present invention thus provides a spacer that not only secures amotor stator within a center shell, but also properly positions astator, and further provides a bearing mount for the shaft.

A related way of adapting a small frame motor to a larger diameter shellis disclosed in co-pending U.S. patent application Ser. No. ______,filed on even date herewith, and entitled “Deformed Shell for HoldingMotor Stator in a Compressor Shell.”

Although a preferred embodiment of this invention has been disclosed, aworker of ordinary skill in this art would recognize that certainmodifications would come within the scope of this invention. For thatreason, the following claims should be studied to determine the truescope and content of this invention.

1. A sealed compressor comprising: a center shell having an innerperiphery of a first diameter; at least one end cap secured to saidcenter shell; a compressor pump unit mounted within said center shell;an electric motor having a stator with an outer periphery of a seconddiameter, said second diameter being smaller than said first diameter,and said stator driving a rotor, said rotor driving a rotating shaft,and said rotating shaft driving said compressor pump unit; and a spacerpositioned between said outer periphery of said stator and said innerperiphery of said center shell, said spacer having a lower plate, saidlower plate including a bearing mount, said bearing mount receiving abearing, and said rotating shaft mounted within said bearing.
 2. Thesealed compressor as set forth in claim 1, wherein said spacer furtherincluding a plurality of circumferentially spaced fingers extending fromsaid lower plate, and said fingers being positioned between said outerperiphery of said stator and said inner periphery of said shell.
 3. Thesealed compressor a set forth in claim 2, wherein an upper extent ofsaid fingers includes a chamfer to facilitate movement of said centershell over said fingers.
 4. The sealed compressor as set forth in claim1, wherein said spacer including a stop, said stator being positioned onsaid stop, with said stop properly positioning said stator along an axisof rotation.
 5. The sealed compressor as set forth in claim 1, whereinsaid lower plate includes a plurality of ribs to provide rigidity.
 6. Asealed compressor comprising: a center shell having an inner peripheryof a first diameter; at least one end cap secured to said center shell;a compressor pump unit mounted within said center shell; an electricmotor having a stator with an outer periphery of a second diameter, saidsecond diameter being smaller than said first diameter, and said statordriving a rotor, said rotor driving a rotating shaft, and said rotatingshaft driving said compressor pump unit; and a spacer positioned betweensaid outer periphery of said stator and said inner periphery of saidcenter shell, said spacer including a stop, said stator being positionedon said stop, with said stop properly positioning said stator along anaxis of rotation of said shaft.
 7. The sealed compressor as set forth inclaim 6, wherein said spacer further including a plurality ofcircumferentially spaced fingers extending from a plate, said plateincluding a bearing mount, and said fingers being positioned betweensaid outer periphery of said stator and said inner periphery of saidshell.
 8. The sealed compressor as set forth in claim 7, wherein saidplate includes a plurality of ribs to provide rigidity.
 10. The sealedcompressor a set forth in claim 7, wherein an upper extent of saidfingers includes a chamfer to facilitate movement of said center shellover said fingers.